The present invention relates to couplings in general, and more particularly to improvements in couplings (hereinafter called hose couplings) which can be used to establish separable but fluidtight connections between pairs of tubular components, especially between a rigid component and a deformable component. Typical examples of such components are nipples or analogous pieces of pipe (hereinafter called pipes) and hoses consisting of flexible material. Still more particularly, the invention relates to improvements in hose couplings of the type wherein the means for securing the hose to the pipe includes a tubular connector.
German Pat. No. 30 01 991 discloses a hose coupling wherein a pawl is provided on a connector to separably lock the connector to the pipe. The pawl is biased to a locking position, in which its pallet engages a radial shoulder of the pipe, by a torsion spring and the pivot for the pawl is carried by a sleeve which surrounds the connector and is movable axially thereon against the opposition or under the action of a coil spring. The purpose of the coil spring is to urge the sleeve and the pawl thereon in a direction to maintain the pallet of the pawl in engagement with the radial shoulder of the pipe. The coil spring reacts against an external shoulder of the connector and bears against an internal shoulder of the sleeve. One end of the connector has a frustoconical external surface which bears against an O-ring and urges the latter against an internal surface of the pipe under the action of the coil spring.
A drawback of the patented coupling is that it comprises an excessive number of component parts including the aforementioned sleeve, a coil spring and a discrete torsion spring for each pawl. Moreover, several component parts of the patented coupling are rather complicated so that their manufacturing cost contributes significantly to the overall cost of the coupling. Furthermore, the patent does not disclose the manner in which the connector can be secured to the hose.
U.S. Pat. No. 3,394,954 discloses a tube coupling for medical appliances wherein a tubular connector is assembled of several parts and serves to establish a path for the flow of a fluid medium between two rubber tubes. The patented coupling is quite complex and the connections between the connector and the rubber tubes are unreliable.
U.S. Pat. No. 4,123,091 discloses a tube coupling with a positive locking connect and ready disconnect. The coupling has several complex parts and its dimensions, as considered in the radial direction, are quite substantial.
Additional hose couplings are disclosed in U.S. Pat. Nos. 1,043,683, 1,312,584 and in British Pat. No. 1,334,486. These couplings are not only bulky but also extremely complex so that they and/or their parts cannot be mass-produced at a reasonable cost which is a prerequisite for the utilization of hose couplings in motor vehicles and the like.